MacDonald started in broadcasting at WPRO (AM) in Providence, Rhode Island.[1] He began working at WBZ (AM) radio in Boston in 1936. When WBZ-TV began television broadcasting in 1948 as an NBC affiliate, MacDonald was the station's first news anchorperson (not called that, as that term was not yet extant).[2] He hosted the station's first broadcast, shown at 6:15 PM on June 9, 1948.[3]

In 1969, after two decades at WBZ-TV, MacDonald was recruited away by WKBG-TV (UHF channel 56) to host its new 10:00 PM newscast, Ten PM News, the first prime time newscast on a commercial television station in the Boston market. The program (which was the first on-air job for Natalie Jacobson) was not a financial success and WKBG-TV dissolved its news department at the end of 1970. MacDonald remained at the station for another year and hosted a weekday morning interview program.[citation needed]

MacDonald at one time or another worked for all three network-affiliated television stations in Boston, and several radio stations, in the course of his 54-year career.[2] He worked up into the year of his death at 73, his last job being editorial director of WRKO radio in Boston.[1]